Art of converting molten slag into a highly-porous mass.



C. H. SCHOL.

ARI 0F CONVERTING MOLTEN SLAG INTO A HIGHLY POROUS MASS.

APPLICATION FILED SEPT. I5. I915.

1,163,605. Patented Dec. 7, 1915.

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Specificationof immanent.

Patented Dec; a, rats.

Application filed- September 15; 19-152 Serial Norflt888.

and useful Improvements in: the Airt 0r- Converting Molten Slag into a Highly fioa rous Mass, of which the following-ins specification.

My invention relates to aprocess of converting molten slag intoa highly porous mass.

For manufacturing lighthrieks of the type of the socalled Rhenish-tufi'bricks it has been proposed to convert blast furnace slag or the like into a highly-porous mass; The granulating of slag Toy-conducting thesame into water is well-known. sudd'en quenching of the slag preventsobtaim i'ng ot-a highly porous structure whichis necessary for the purpose mentioned-above.

It has therefore been proposed} already to subject the molten blast-furnacesl'ag, con: ducted into water, to the action;- of{ compressed air rising from the bottomofthe reservoir in a finely divided state so that the lumps of slag floating on the surface are caused to swell bythe'act-ion ozt-jsteam and air simultaneously.

I have now found that in order toobtain a structure as porous as possible, it is-necessary to prevent the formation ot-a glassy" layer on the under surfaceof the slagwhichis formed regularly in the granulating processes usedfhitherto as soon as the slag comes into contact with the-water andfwhich layer prevents entering of the water into-the.-in-

terior of the slag. In order to convertthe slag into a porous mass it'has been necessary up to now to break up this hard glassy layer,

so as to allow the water entering into the interior of the slag.

The-ob ect of my invention is-therefore to convert the slag slowly into a,porous mass,

instead of-suddenly, so that the time of actionof the steam produced upon-the slag'is extended as long as possible for the-purpose of obtaining a swelling of'the slag-as far as possible.

Contrary to th'eold process according to which the slag is plunged into cold water from a considerable height, the new-process consists mainly in this thatthe slaggis conductedinto the granulating-water in a level which is approximately equaltothatof the water, and-that the granulating water in;

' of cement. According to the present invenand 430'oi the book Die Ckemache Tech-n0- face, but this was intended only to prevent sinking of the slag in which case the slag was taken oh the water surface before it sunk. This known process of introducing the slag into the granulating water has been proposedpnd is suitable for the production than the slag is introduced in the same inanner; hut-is subjected'to the action of the steam, generated by the contact of the molten slagwith the water, for a longer period oftime in order to obtain a structure as porous as possible;

In order to convert the slag into a porous massithas also been proposed to first prepare-the slag'in a drain-pond and then to introduce itinto-the second pond filled partly with water, where it is converted into a porous. mass. Hereby the water is heated as this is always the case when introducing slag: This process described on pages 429 logic dew Mo'rtelmatem'alz'en, edited by Feicht-inger; in 1885 does not allow uninterrupted working. The essential point is however'that the slag does not come into contact witli'highly heated water at once, but that the slag brings the water gradually to a relative high temperature. In the granulating-processes known hitherto, cold water is-always introduced together with the slag, as'the slag takes with it a great amount of the water, and fresh water always must flow in. The fresh water flowing in is after- Ward heated by the slag already converted into a solid mass, so that in the processes known hitherto the slag introduced comes into contact with cold water always.

In contradistinction to the known procasses the feature of my invention consists in this that in the moment of introducing, the slag-comes into contact with hot water the temperature of which is as near as possible to that of the boiling point, so thatsteam may be produced as soon as the slag enters the: water and that first of all the contacting surface of the slag remains soft and quenching is prevented which is always the case the known processes. The slag may also be caused to flow across an inclined perforated surface through the holes of which steam under a certain pressure rises from below, causing it to swell to large porous lumps. The steam must however not be introduced under too high a pressure as otherwise the large lumps which I intend to receive will not be produced, but the slag will be dispersed and crushed.

In carrying out the process difi'erent forms may be adapted; it is however neces sary that the steam easily penetrates the slag from below and causes it to swell considerably without efiectin a dispersing or crushing of the slag. A fter swelling the material may be conveyed to the place of further treatment by means of a conveyer or the like.

The figure is a longitudinal sectional view of the preferred apparatus capable of carrying out the present process.

The trough or channel a conveying the slag from the blast furnace to the water receptacle b terminates as this is usually the case in a level a little above the water level. The slag does not plunge into the water directly, but falls upon'an inclined surface or wall 0 projecting only a little above the water level. As shown in the drawing, the surface or wall 0 belongs to a box-like reservoir d to which the granulating water is conducted by means of a pipe for the purpose of cooling at least the under side of the inclined surface 0 to such an extent that it can not be destroyed by the molten slag with which'it comes into contact. The inclined surface 0 may however not be cooled so far that the slag is quenched when coming into contact therewith.

The water in the reservoir 01 is of course highly heated and is conducted by a pipe 7 to a place in the receptacle I) which is spaced apart as far as possible from the point of introduction of the slag into the water. This is preferably because the water at the point of introduction of the slag is highly heated and in any case is Warmer than the water heated in the reservoir at only. According to the present invention however the slag must on entering the receptacle 6 at once come into contact with water heated as I high as possible.

The front part of the box 2' is provided with an inclined hollow wall Z which may be cooled by water. The inclined wall I is rovided with a great amount of perforations m through which the steam may escape. The trough or channel a in this case is so arranged that the slag drops directly upon the incllned wall I over which it flows into the receptacle 6. Hereby the slag is subjected to the action of the steam passing through the holes at and is caused to swell before the samepasses into the granulating water within the receptacle. s

It will be understood that the plants described for carrying out the new process may be substituted by any other suitable plant.

I claim 1. The process of converting blast furnace slag into a bi hly porous mass, which consists in intro ucing the slag into highly heated granulating water.

2. An apparatus forconverting blast furnace slag into ahighly porous mass comprising a receptacle having granulating water therein, a reservoir within the receptacle and having one of its walls lying near the surface of the granulating water over which the molten slag passes into'the receptacle to heat the water beneath thesaid wall,

and means communicating with the reservoir for transferring a portion of the heated water therein to the receptacle.

3. An apparatus for converting blast furnace slag into a highly porous mass comprising a receptacle having granulating water therein, a reservoir having an inclined upper wall positioned near the surface of the water within the receptacle and over which he slag flows into the receptacle to heat the water in the reservoir beneath the said inclined wall, and means for transferring a portion of the heated water under the inclined wall to a point distant to where the slag is introduced into the receptacle.

4. An apparatus for converting blast furnace slag into a highly porous mass comprising a receptacle having granulating water therein, means for supporting the slag while the same flows near the surface of a portion of water within the receptacle to heat the water beneath the slag before the slag is deposited within the receptacle, and means for transferring a portion of the Water heated by the flowing slag to a point distant from where the slag is introduced in the receptacle.

In testimony whereof I have afiixed my signature in presence of two witnesses CARL H. soHo Witnesses B. Jommoonr, E. Faan'rz. 

